<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
			let str = '东软睿道Java7班';
			let a = str.substring(4);
			console.log(a);
			let b = str.substring(1,7);// 7> ? >= 1 
			console.log(b);
		</script>
	</body>
</html>
